Treatment of artificial textile



Patented Sept. 16,1941

TREATMENT OF ARTIFICIAL TEXTILE MATERIALS Henry Dreyfus, London, England No Drawing. Application September 29, 1938, Se-

rial No. 232,353. 1937 This invention relates to improvements in the manufacture of artificial materials, and particularly to improvements in the manufacture of artificial filaments, yarns and similar materials having a basis of cellulose acetate or other organic derivative of cellulose.

In knitting, weaving and other textile operations it is well known that humidity either in the atmosphere or associated with the materials is of importance since it plays a very considerable part .a determining the flexibility of the materials undergoing these mechanical treatments and a proper adjustment of the humidity is essential to the production of good results.

Certain operations to which textile materials of organic derivatives of cellulose may be subjected during or subsequent to their formation may yield products having a smaller ability to absorb moisture than the materials obtained directly by the normal dry spinning process and in consequence the normal methods of achieving the best results in knitting, weaving and other operations are either not applicable at all or give less satisfactory results than with ordinary textile materials. Among such operations are processes in which artificial filaments and, the like are stretched in the presence of hot water or steam or, during or subsequent to their production, in solutions of swelling agents or organic solvents to increase their tenacity, and processes in which they are esterified.

I have now found that the properties, and particularly the flexibility, of artificial filaments, yarns and similar materials made of organic derivatives of cellulose which have been subjected to such operations, for example the stretching and esteriflcation processes referred to above, may be improved by incorporating suitable plasticisers in the materials. Preferably, the incorporation is effected after the completion of the operation, though it may, if desired, be effected before such treatment when the latter is an after-treatment or even prior to the formation of the materials by incorporating the plasticisers in the spinning solution from which the materials are produced.

Examples of plasticisers which may be employed in accordance with the process of the present invention are para-toluene sulphonamide and para-toluene methyl sulphonamide, tributyl phosphate, dibutyl phthalate, dimethyl glycol phthalate, diethyl glycol phthalate, .dibutyl tartrate and diacetin. Preferably, plasticisers which are hydrophile or even soluble in water to a slight extent are employed.

In Great Britain October 26, 5 Claims. (01. 8-129) An improvement in the flexibility of the materials may be effected by the incorporation of a comparatively small proportion of plasticiser, for example from I to 2 up to 5% of the weight of the materials, and preferably the amount incorporated is of this order. Higher proportions, for example 1001' 20% or even more, may be incorporated if desired, but too high a proportion of plasticiser may tend to make the materials plastic so that they are easily deformed by even slight tension or pressure.

Incorporation of the plasticiser in the materials may be eifected by treating the materials with a liquid medium containing the plasticiser in the form of a. solution or of an emulsionor suspension in a suitable liquid medium which does not dissolve the base of the artificial materials or swell it to too great an extent. A certain amount of swelling may be of value in assisting the incorporation. Examples of suitable liquids are water, alcohol, benzene, toluene, ethyl acetate, diethyl ether, di-isopropyl ether, ligroin and cyclohexane. Solutions of suitable substances may also be employed, for example solutions of methylene or ethylene dichloride in benzene or carbon tetrachloride, aqueous solutions of acetene, methylene ethylene etherand other solvents for the organic derivatives of cellulose,

Example 1 A cellulose acetate yarn which has been stretched in wet steam according to the process described in U. S. application 8. No. 48,084 filed 4th November 1935, is immersed in bank form in a 2% aqueous emulsion of dibutyl tartrate containing a small proportion of the emulsifying agent sold under the registered trademark Igepon. Th emulsion is maintained at about C. When sufllcient dibutyl tartrate has been absorbed by the yarn the latter is withdrawn from the treating liquid, and dried.

j yarns and I an organic derivative of cellulose have their 1 ability to absorb moisture reduced by stretching forming operation.

ther acetylated with acetic anhydride in the presence of ferric chloride and hydrochloric acid according to the process described in U. S. ap-

a bath of 4 parts of p-toluene-sulphonamide in 100 parts of 3% aqueous ammonia until suflicient plasticiser has been taken up. The hanks are then withdrawn and dried.

' Similar proportions of other plasticisers, which 1 are preferably hydrophile, may be substituted for the dibutyl tartrate and p-toluene-sulphonamide specified in the examples.

Having described my invention, what I desire to secure by Letters Patent is:

1. In processes wherein artificial filaments, ar materials having a basis of in the presence of hot water, steam or organic solvents or swelling agents, the step of restoring the ability to absorb moisture which comprises incorporating a plasticizer in the materials after they have been subjected to the stretching operation but before they are subjected to a fabric- 2. In processes wherein artificial filaments, yarns and similar materials having a basis of an organic derivative of cellulose have their ability to absorb moisture reduced by stretching-in the presence of hot water, steam or organic solvents or swelling agents and are esterified, the step of restoring the ability to absorb moisture which comprises incorporating a plasticizer in the materials after the stretching and esterifying op- I plication S. No. 39,290 filed 5th September 1935, Patent No. 2,159,012, is soaked in hank form in erations-but before they are subjected to a fabric-forming operation.

3. In processes wherein artificial filaments, yarns and similar materials having a basis of cellulose actate have their ability to absorb moisture reduced by stretching in the presence of hot water, steam or organic solvents or swelling agents, the step of restoring the ability to absorb moisture which comprises incorporating a hydrophile or slightly water-soluble plasticizer in the materials after they have been subjected to the stretching operation but before they are subjected to a fabric-forming operation.

4. In processes wherein artificial filaments, yarns and similar materials having a basis of an organic derivative of cellulose have their ability to absorb moisture reduced by stretching in the presence of hot water, steam or organic solvents or swelling agents, the step of restoring the ability to absorb moisture which comprises incorporating a sulphonamide in the materials in a proportion up to 5% ofthe weight of the materials after they have been subjected to the stretching operation but before they are subjected to a fabric-forming operation.

5. In processes wherein artificial filaments, yarns and similar materials having a basis of cellulose acetate have their ability to absorb moisture reduced by stretching in the presence of hot water, steam or organic solvents or swelling agents, the step of restoring the ability to absorb moisture which comprises incorporating a sulphonamide in the materials in a proportion up to 5% of the weight of the materials after they have been subjected to the stretching operation but before they are subjected to a fabricforming' operation.

' HENRY DREYFUS. 

